Carton blank



N 9, 96 J. c. BRACKETT 3,288,348

CARTON BLANK Filed March 23, 1964 34 *1? INVENTOR P JOHN C. 53/46/4577 ATTORNEY United States Patent 3,288,348 CARTON BLANK John C. Brackett, St. Paul, Minn., assignor to Waldorf Paper Products Company, St. Paul, Minn., a corporation of Minnesota Filed Mar. 23, 1964, Ser. No. 353,963 1 Claim. (Cl. 229-67) This invention relates ot an improvement in reinforced cartons and deals particularly with a carton designed for use in containing a powdered or granulated material which normally has a tendency to cause the walls of the package to bulge, and in a method of making the same.

When a material such as flour, powdered milk and the like is packaged in rectangular tubular cartons, the weight of the material has a tendency to bulge the carton walls outwardly. This tendency is increased as the stiffness and rigidity of the paperboard decreases. Where the product is contained in a carton made of thick rigid paperboard, little trouble is experienced. However, packages of this type are expensive, and tend to bring the cost of packaging relatively high as compared to the cost of the product. Accordingly, during recent years, there has been a trend toward making the cartons of lighter weight board, and connecting intermediate portions of the larger panels of the cartons with connecting strips which restrain the panels from bulging outwardly.

Various methods have been employed for producing cartons having such reinforcing strips. For example, Patent 3,029,711 granted on April 17, 1962, to Robert W. Griese discloses a method of forming a carton of the type in questions which includes the steps of applying areas of adhesive to the inner surfaces of portions of the two main panels while the blank is flat, applying one end of a partition strip to one of the adhesive coated areas, and folding the carton so that the other adhesive coated area becomes adhered to the other end of the partition strip. While this method has been successful, it is somewhat diflicult to control so that the adhesive coated areas do not extend beyond the confines of the partition strip, in which case the walls of the carton will be glued together, creating a problem in opening the cartons.

Patent 3,106,876, issued October 15, 1963, to Ernest J. Dewhurst discloses another method of forming a similar reinforced carton. In this structure, an extension is provided at one end of the carton blank and by folding this extension and the adjoining wall to overlie one of the larger carton panels, the extension may be glued to an intermediate portion of the large panel, and the extension may be held in place while the carton panel to which the extension was connected is severed from the extension and folded outwardly. The carton may then be folded to adhere the other large carton panel to the other end of the extension, and the manufacturers joint may *be sealed in the conventional manner. This arrangement is also successful in actual practice although the shape of the carton is somewhat restricted. Furthermore, in order for the extensions on two adjoining panels to dovetail to conserve paperboard, the connecting partition must be at one end only of the carton.

I have found that certain of the previous difiiculties may be eliminated by providing an extension on one of the closing flaps designed to close the end of a tubular carton. With this arrangement, the connecting partition may be located at a point spaced from an end of the carton a distance equal to the length of the closing flap. As a result, the connecting partition may be located at a point more nearly adjacent to the center of the wall panels. Furthermore, two cartons having similar extensions may be dovetailed together as the extensions are always located on one side of the center of the blank.

This arrangement also provides anchoring flaps of much larger area on opposite ends of the partition strip than are usually practical when the extension is hinged to an edge of the blank. Thus the particular arrangement disclosed has certain advantages over the previous methods employed.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specifications and claims.

In the drawings forming a part of the specification:

FIGURE 1 is a perspective view of a closed carton, portions of one side wall being broken away to disclose the interior construction.

FIGURE 2 is a diagrammatic view of the blank from which the reinforced carton is formed.

FIGURE 3 is a diagrammatic view of the blank after the first folding operation.

FIGURE 4 is a diagrammatic view of the flat folded blank.

FIGURE 5 is a horizontal sectional view through the carton in erected form.

The Carton A is formed of the blank best illustrated in FIGURE 2 of the drawings. The blank includes a first main panel 10, a side wall panel 11, a second main wall panel 12, and a second side Wall panel 13 foldably connected toegther along parallel fold lines 14, 15, and 16. A glue flap 17 is hingedly connected to one end of the blank, the glue flap 17 being shown as hinged to the edge of the main panel 10 along the fold line 19.

Top closing flaps 2t), 21, 22, and 23 are hinged to the upper edges of a panel 10, 11, 12, and 13 along a fold line 24. Similar closure flaps 25, 26, 27, and 29 are hinged to the lower edges of the panels 10, 11, 12, and 13 along a fold line 30. To this point, the carton A simulates a conventional paste end carton.

A partition unit or structure which is indicated in general by the numeral 31 is hingedly connected to the free edge 32 of the closing flap 27 hinged to the main panel 12. The partition structure is connected to the flap 27 along a weakened line of separation 33 which permits the partition structure to be easily separated from the flap. The weakened line 33 is parallel to the fold line 30 connecting the closure flaps to the carton panels.

The partition structure 31 includes a center partition panel 34 which is of a width substantially equal to the width of the side walls 11 and 13. Thi partition panel 34 is connected to anchoring flaps 35 and 36 along parallel fold lines 37 and 39 which are parallel to the fold lines 14, 15, and 16. In preferred form, the fold line 39 is on a line substantially midway between the side edges 15 and 16 of the main panel 12.

In forming the carton A, the following method is employed. Adhesive is applied to the surface of the anchoring flap 36 which will be in face contact with the main panel 12 when the closing flap 27 is folded through degrees. The adhesive coated area may alternatively be applied in the area 40 designated by broken lines on the panel 12. The closing flap 27 is then folded along the fold line 30 until the partition structure and the flap 27 overlie portions of the wall panel 12. The flap 27 is shown as extending somewhat beyond the adjoining flaps 26 and 29 so as to simplify the engagement of the flap for folding purposes. When the flap 27 has been completely folded, it appears as indicated in FIGURE 3 of the drawings and the anchoring flap 36 is adhered to the surface of the panel 12 within the area 40.

The closing flap 27 is then folded outwardly to its starting position while the partition structure 31 is held is held in contact with the panel 12. This is usually accomplished by folding the flap 27 over a sword or flat blade overlying the lower portion of the panel 12, the

blade being curved or angled at its end to raise the flap 27 away from the surface of the panel 12 while the partition structure is held against the panel 12. Adhesive is then applied to the anchoring flap 35 and the glue flap 17 and the blank folded along the fold lines 14 and 16. This operation adheres the anchoring flap 35 to the innersurface of the panel 10 and adheres the glue flap 17 underlying the side wall 13. The folded carton then appears as indicated in FIGURE 4 of the drawings.

When the carton is squared up as indicated in FIG- URE 5 of the drawings, the panel 34 forms a partition panel anchored at one end to one main panel 10 and at its other end to the opposite main panel 12. As is also indicated, the connecting partition is anchored to the panels 10 and 12 at points spaced at substantially above the lower fold line 30. Thus the partition connects the center of the main panels along approximately the area where the bulge is most likely to occur. The vertical length of the partition may be increased or decreased in order to provide an effective connection for the particular product being packaged and the nature of the paperboard employed. By using the partition structure, the grade of paperboard employed may be much lower than would be otherwise required for the purpose.

In accordance with the patent statutes I have described the principles of construction and operation of my reinforced carton, and while I have endeavored to set forth the best embodiments thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

A carton blank for use in forming a partitional carton, the blank including:

a first side panel, a first main panel, a second side panel, and a second main panel connected in series along parallel fold lines, the distance between the fold lines comprising the width of the panels,

closure flaps hingedly connected to each of said panels along a substantially common line of fold intersecting the said parallel fold lines at substantially right angles, the distance between the common line of fold and the opposite edges of the panels comprising the length of these panels,

a partition panel structure connected to the closure flap on said first main panel along a weakened line of separation parallel to said common line of fold,

the combined lengths of said closure flap on said first main panel and the partition panel structure being less than the length of said panels,

said partition panel structure being divided into an intermediate partition panel and opposite disposed anchoring flanges by a pair of parallel fold lines spaced apart a distance substantially equal to the width of said side panels,

one of said lines of fold of said pair which is nearest the end of the blank including said first side panel being on a line parallel to and substantially midway between the fold lines connecting said first main panel to said first side panel and said second side panel,

said anchoring flanges being adapted to fold into face contact with said opposite main panels when said first main panel closure flap and said partition panel structure is folded therebetween.

References Cited by the Examiner UNITED STATES PATENTS 2,880,921 4/ 1959 Persson 229-28 2,998,179 8/1961 Zilles.

3,029,711 4/ 1962 Greise 22929 3,106,876 10/ 1963 Dewhurst 22927 X JOSEPH R. LECLAIR, Primary Examiner.

J. F. MCNULTY, D. F. NORTON, Assistant Examiners. 

